Such an offshore construction is known from WO 00/78599 in which a mooring buoy is disclosed which is anchored to the seabed in which the anchor chains are attached to the buoy via a pivoting chain receiving tube comprising a chain stopper by which the chain can be tensioned. By providing two orthogonal pivot axes for the chain tensioner, chain wear can be reduced and the tension in the chain upon movement of the buoy is decreased.
As is known generally, floating devices such as vessels or floating offshore structure, for example in the oil and gas industry, are moored to the seabed with one or more mooring lines. The floating device is kept on location because of the catenary effect of the mooring chains. A shift of the floating device leads to a lifting or lowering of the mooring chains, which leads to a counter effect striving to re-establish the original position of the floating device. The floating device is provided with a mooring chain connector assembly for each mooring chain, wherein the first pivot axis allows motions of the mooring chain in its catenary plane (so-called “in-plane motions”). It is also known to provide a second pivot axis, typically perpendicular to the first pivot axis, which second axis allows motions of the mooring chains in a transverse direction (so-called “out-of-plane motions”). In this manner fatigue problems in the mooring chain related to any motions of the mooring chain are minimized.
Mooring chain connector assemblies of this type are described for example in U.S. Pat. No. 6,663,320 filed by the applicant.
In the known mooring chain connector assemblies, the chain connector chain connector consists of articulations and a long lever arm to follow the mooring lines movements. That long lever arm hanging below the chain table requires a lot a space which is not available in dry dock or at quay side. The sea fastening is also a concern due to the high current and inertia loads acting on the lever arm.
The present invention provides a solution where the chain connector will no longer hang below the chain table when there is no space available nor while sailing without the need to move the whole chain connector from a first location to a second location above water level as described in EP2154059.
According to the present invention, the operation required, to avoid having neither the chain connector hanging when there is no space available nor while sailing, is eased and not time consuming. The solution proposed removes the critical path of installation operation, it renders the connectors easier to handle and hence the relocation of a floating unit is eased.
Further according to the present invention, the chain is protected against corrosion and the sling arrangement is simplified.